The present invention relates generally to a belt cleaning arrangement disposed adjacent the end of a conveyor belt to remove all traces of conveyed material.
In use presently are trucks which transport unmixed concrete materials to a using site whereat they are mixed and discharged. Stone, sand and cement are transported in bins and combined on a truck mounted conveyor belt. Water is added prior to discharge of the ingredients at a pour site. U.S. Pat. Nos. 3,310,293 and 3,339,898 disclose both truck and mixing trough structure analogous to that currently used on such trucks.
Existing belt arrangements on such trucks make no provision for washing of the belt exterior surface on the lower or return belt run. A scraper is provided but is of reduced effectiveness after wear of the scraper blade. During a delivery operation, that street or ground area below the truck is usually contaminated by concrete ingredients. The truck operator, in some locales, must expend time and effort to clean up the site prior to departure or otherwise subject the truck owner to a fine for violating various environmental ordinances.
A further drawback to known conveyor construction is the loss of those materials which cling to the belt return run and ultimately fall onto the ground. While each instance of an unloading operation results in but a relatively small loss, the cumulative loss over several months is of some value.
Further, belt life is markedly diminished by the accumulation of concrete ingredient particles thereon which particles may ultimately work themselves to the inner side of the belt.
To the extent known, the prior art discloses the general concept of belt cleaning utilizing brushes, scrapers, etc., along with water sprays but does not provide same useable in a manner compatible with the conveyor of a concrete truck nor in combination with a mounting ring supporting a delivery trough common to such machines. Belt cleaning arrangements using water, air, brushes and/or scrapers are disclosed in the following U.S. Pat. Nos. 263,634; 1,543,411; 3,414,116; 1,793,246; 3,815,728; 3,875,613; 3,865,232; 4,182,444 and 3,402,805 all disclosed without regard to a mounting ring assembly.